And the thermometer is showing 86..is it the kind that goes under the rocks?

yes my dad removed it for a water change and now Tarnish is laying on the bottom so I didn't want to disturb him or cause him even more stress so it's sitting off to the side, as low down as I could put it to warm the water

If his water is at 86* you really should turn that heater off. I think I know which one you're talking about and I use them in my 3 gallon and 2.5 gallon tanks. They raise the water temperature about 5 degrees in my tanks and are very gradual. If you see the temp drop below 80 turn it back on, but 86 seems to be really warm.